a. Field of the Invention
The invention relates generally to apparatus for generating power from the combined energy of the wind and the sun.
b. Prior Art
There are many well known power generation devices that convert the energy of the wind or solar energy into another, more convenient, form of energy, such as electrical energy or rotary mechanical energy. Common examples of devices utilizing wind energy are the wind powered generators and the wind powered water pumps found on many farms and ranches throughout the world.
There are also a great number of power generation devices which convert solar energy into another, more easily utilized energy form. One common method for converting solar energy into mechanical energy is to use solar energy to create a tempereature difference between two or more bodies of fluid (or between a body of fluid and the ambient environment) that can be used to actuate bellows, pistons or other devices. Examples of solar energized devices of this type are found in the disclosures of Bonaventura et al. in U.S. Pat. No. 2,688,923, Sherock in U.S. Pat. No. 3,112,862, Green in U.S. Pat. No. 3,023,167, Booth in U.S. Pat. No. 3,309,012, Schuman in U.S. Pat. No. Re. 27,740, Thureau et al. in U.S. Pat. No. 3,937,599, Kirsten in U.S. Pat. No. 3,972,651, Lapeyere in U.S. Pat. No. 3,304,985 and Neidigh in U.S. Pat. No. 3,989,417.
A somewhat different mechanism utilizing the same principle as the devices of the above cited patents is disclosed in U.S. Pat. No. 4,041,707 of Spector which teaches a device that utilizes the temperature difference between the surface water and the water of the lower depths of a large, naturally occurring body of water. A piston is energized by air heated or cooled within heat transfer coils that are disposed both near the top and bottom of the body of water.
All of the above cited patents disclose devices which utilize solar energy to heat a body of fluid so that its temperature can be raised above that of another body of fluid. None of the above devices, however, attempt to lower the temperature of a body of fluid so as to further increase the magnitude of the temperature difference.
In U.S. Pat. No. 4,068,476 of Kelsey, a power unit is disclosed which uses a solar evaporator to power a hydraulic pump that drives a hydraulic motor. Thus, Kelsey's device differs from previously cited devices in that it utilizes solar generated gaseous vapors to perform mechanical work rather than the temperature difference between two bodies of fluid or between a body of fluid and the ambient environment.
A problem the prior art has not adequately addressed is how to provide a temperature difference type power generation device that utilizes solar energy to heat a first body of fluid and wind energy to cool a second body of fluid so as to maximize the temperature difference between the bodies of fluid and to increase the potential power output of the device. One approach is described in my copending U.S. patent application Ser. No. 898,299, now U.S. Pat. No. 4,150,923.